The present invention is directed to a sensor for detecting movement of a sheet of media, and more particularly, to a reflective optical sensor for detecting movement of a sheet.
Electronic office equipment, such as printers, copies, facsimile machines, scanners, business machines and the like typically move sheets of paper, transparencies or other media from an input tray to a printing area, and from the printing area to an exit or storage tray. The office equipment may include a number of sheet-detecting sensors located along the page of movement of the sheet to detect the presence or absence of a sheet. However, such sensors only detect the presence or absence of a sheet, and can not detect the state of movement of a sheet.
The electronic office equipment may also include a media sensor to determine the media type of the sheet located within the input tray. The media sensor typically includes a light emitting element and a light sensing element that detects light emitted by the light emitting element and reflected by the sheet of media. The amount of light sensed by the light sensing element is fed to a processor to determine the type of media. However, such media sensing sensors do not detect the movement of the examined sheet. Accordingly, there is a need for a sensor for detecting movement of a sheet. There is also a need for a sensor that can detect the media type of sheet as well as movement of the sheet.
The present invention is a sensor for detecting movement of a sheet, and a sensor for detecting media type of a sheet as well as movement of the sheet. In one embodiment, the invention is a sensor for detecting movement of a sheet of media including a light emitting element and a light sensing element for detecting at least part of the light emitted from the light emitting element and reflected by the sheet, the light sensing element providing an output. The sensor further includes a processor receiving the output of the light sensing element and detecting movement of the sheet based upon the output.